From 5c6973699496b17f47fce05d0bddd201445feea4 Mon Sep 17 00:00:00 2001
From: Jae Kwon <jkwon.work@gmail.com>
Date: Fri, 17 Oct 2014 01:01:59 -0700
Subject: [PATCH] Add PartSet test.

---
 consensus/part_set.go      | 22 +++++++++++
 consensus/part_set_test.go | 79 +++++++++++++++++++++++++++++++++++++-
 merkle/util.go             |  4 +-
 merkle/util_test.go        | 35 +++++++++++++++++
 4 files changed, 137 insertions(+), 3 deletions(-)
 create mode 100644 merkle/util_test.go

diff --git a/consensus/part_set.go b/consensus/part_set.go
index a7724795..036ea8a3 100644
--- a/consensus/part_set.go
+++ b/consensus/part_set.go
@@ -4,7 +4,9 @@ import (
 	"bytes"
 	"crypto/sha256"
 	"errors"
+	"fmt"
 	"io"
+	"strings"
 	"sync"
 
 	. "github.com/tendermint/tendermint/binary"
@@ -59,6 +61,26 @@ func (pt *Part) Hash() []byte {
 	}
 }
 
+func (pt *Part) String() string {
+	return pt.StringWithIndent("")
+}
+
+func (pt *Part) StringWithIndent(indent string) string {
+	trailStrings := make([]string, len(pt.Trail))
+	for i, hash := range pt.Trail {
+		trailStrings[i] = fmt.Sprintf("%X", hash)
+	}
+	return fmt.Sprintf(`Part{
+%s  Index: %v
+%s  Trail:
+%s    %v
+%s}`,
+		indent, pt.Index,
+		indent,
+		indent, strings.Join(trailStrings, "\n"+indent+"    "),
+		indent)
+}
+
 //-------------------------------------
 
 type PartSet struct {
diff --git a/consensus/part_set_test.go b/consensus/part_set_test.go
index ce766088..7e7ad8b2 100644
--- a/consensus/part_set_test.go
+++ b/consensus/part_set_test.go
@@ -1,9 +1,86 @@
 package consensus
 
 import (
+	"bytes"
+	"io/ioutil"
 	"testing"
+
+	. "github.com/tendermint/tendermint/common"
 )
 
 func TestBasicPartSet(t *testing.T) {
-	// XXX this is fun!
+
+	// Construct random data of size partSize * 100
+	data := RandBytes(partSize * 100)
+
+	partSet := NewPartSetFromData(data)
+	if len(partSet.RootHash()) == 0 {
+		t.Error("Expected to get rootHash")
+	}
+	if partSet.Total() != 100 {
+		t.Errorf("Expected to get 100 parts, but got %v", partSet.Total())
+	}
+	if !partSet.IsComplete() {
+		t.Errorf("PartSet should be complete")
+	}
+
+	// Test adding parts to a new partSet.
+	partSet2 := NewPartSetFromMetadata(partSet.Total(), partSet.RootHash())
+
+	for i := uint16(0); i < partSet.Total(); i++ {
+		part := partSet.GetPart(i)
+		//t.Logf("\n%v", part)
+		added, err := partSet2.AddPart(part)
+		if !added || err != nil {
+			t.Errorf("Failed to add part %v, error: %v", i, err)
+		}
+	}
+
+	if !bytes.Equal(partSet.RootHash(), partSet2.RootHash()) {
+		t.Error("Expected to get same rootHash")
+	}
+	if partSet2.Total() != 100 {
+		t.Errorf("Expected to get 100 parts, but got %v", partSet2.Total())
+	}
+	if !partSet2.IsComplete() {
+		t.Errorf("Reconstructed PartSet should be complete")
+	}
+
+	// Reconstruct data, assert that they are equal.
+	data2Reader := partSet2.GetReader()
+	data2, err := ioutil.ReadAll(data2Reader)
+	if err != nil {
+		t.Errorf("Error reading data2Reader: %v", err)
+	}
+	if !bytes.Equal(data, data2) {
+		t.Errorf("Got wrong data.")
+	}
+
+}
+
+func TestWrongTrail(t *testing.T) {
+
+	// Construct random data of size partSize * 100
+	data := RandBytes(partSize * 100)
+	partSet := NewPartSetFromData(data)
+
+	// Test adding a part with wrong data.
+	partSet2 := NewPartSetFromMetadata(partSet.Total(), partSet.RootHash())
+
+	// Test adding a part with wrong trail.
+	part := partSet.GetPart(0)
+	part.Trail[0][0] += byte(0x01)
+	added, err := partSet2.AddPart(part)
+	if added || err == nil {
+		t.Errorf("Expected to fail adding a part with bad trail.")
+	}
+
+	// Test adding a part with wrong bytes.
+	part = partSet.GetPart(1)
+	part.Bytes[0] += byte(0x01)
+	added, err = partSet2.AddPart(part)
+	if added || err == nil {
+		t.Errorf("Expected to fail adding a part with bad bytes.")
+	}
+
 }
diff --git a/merkle/util.go b/merkle/util.go
index 56f808e2..ab32740b 100644
--- a/merkle/util.go
+++ b/merkle/util.go
@@ -190,7 +190,7 @@ func HashTrailForIndex(hashTree [][]byte, index int) [][]byte {
 		trail = append(trail, hashTree[next])
 
 		index = (index + next) / 2
-		offset += stride
+		offset += stride / 2
 		stride *= 2
 	}
 
@@ -216,7 +216,7 @@ func VerifyHashTrailForIndex(index int, leafHash []byte, trail [][]byte, rootHas
 			tempHash = HashFromTwoHashes(trail[i], tempHash)
 		}
 		index = (index + next) / 2
-		offset += stride
+		offset += stride / 2
 		stride *= 2
 	}
 
diff --git a/merkle/util_test.go b/merkle/util_test.go
new file mode 100644
index 00000000..a23ba67a
--- /dev/null
+++ b/merkle/util_test.go
@@ -0,0 +1,35 @@
+package merkle
+
+import (
+	. "github.com/tendermint/tendermint/common"
+
+	"testing"
+)
+
+// TODO: Actually test. All this does is help debug.
+// consensus/part_set tests some of this functionality.
+func TestHashTreeMerkleTrail(t *testing.T) {
+
+	numHashes := 5
+
+	// Make some fake "hashes".
+	hashes := make([][]byte, numHashes)
+	for i := 0; i < numHashes; i++ {
+		hashes[i] = RandBytes(32)
+		t.Logf("hash %v\t%X\n", i, hashes[i])
+	}
+
+	hashTree := HashTreeFromHashes(hashes)
+	for i := 0; i < len(hashTree); i++ {
+		t.Logf("tree %v\t%X\n", i, hashTree[i])
+	}
+
+	for i := 0; i < numHashes; i++ {
+		t.Logf("trail %v\n", i)
+		trail := HashTrailForIndex(hashTree, i)
+		for j := 0; j < len(trail); j++ {
+			t.Logf("index: %v, hash: %X\n", j, trail[j])
+		}
+	}
+
+}